id: 05701690
dt: j
an: 2010b.00634
au: Gårding, L.
ti: Food chains. (Näringskedjor.)
so: Normat. 57, No. 2, 74-77 (2009).
py: 2009
pu: Nationellt Centrum för Matematikutbildning (NCM), Göteborgs Universitet,
Göteborg
la: SV
cc: M60 I70
ut: mathematical modelling; linear model; stability condition
ci:
li:
ab: Summary: A food-chain is an ordered collection of populations feeding on
each other. A simple linear model for the variations of the populations
is introduced. A condition for stability, i.e., that the variations of
the populations are bounded, is that all the eigenvalues of the
corresponding matrices lie on the unit-circle. The populations will
then vary cyclically. The condition gives some restrictions on the
fertility and life-expectancies of the various populations. Special
cases of simple chains are studied and compared with real-life data,
with some remarkable good fits.
rv: